Impulse transmitting device



Feb. 19, 1946. H. HANSEN ET AL IMPUL SE TRANSMITTING DEVICE Filed Dec.4, 1941 2 Sheets-Sheet 1 IN VE/V TOkS HANSEN By R.F. MALL/NA MKWWM A rTOR/YE y Feb. 19, H, HANSEN ET AL IMPULSE TRANSMITTING DEVICE' FiledDec. 4, 1941 2 Sheets-Sheet 2 WVENTORSW. F. MALL lNA TWK L AT TORNEV H.HANSEN Patented Feb. 19, 1946 IMPULSE TRANSMITTING DEVICE Harry Hansen,Clifton, N. .L, and Rudolph F. Mallina, Hastings on Hudson, N. Y.,assignors to Bell Telephone Laboratories, Incorporated, New York, N. Y.,a corporation of New York Application December 4, 1941, Serial No.421,572

2 Claims.

This invention relates to impulse transmitting devices and particularlyto improvements in such devices for use in controlling the operation ofswitches in automatic telephone systems.

An object is to simplify the construction and improve theoperatingcharacteristics of such de- VlCeS.

Heretofore impulse transmitting devices have been provided in which keysor push-buttons terminating in extensions. operate on bars or levers tocontrol them in combinations. Such bars may operate on contacts to closecorresponding combinations of connections to establish code signals,while in other instances such levers may operate on reeds incombinations to transmit dilferent combinations of frequencies over aline to control switches at a. central mice.

It is in connection with impulse transmitting devices of this generalcharacter that the present invention is concerned, and a feature thereofis an arrangement of a set of push-buttons in a single row in atelephone stand and in which a plurality of U-shaped levers are providedwith different combinations of extension fingers on which thepush-buttons act directl when depressed to rotate the levers indifferent combinations depending on the number and arrangement of suchfingers acted upon by each push-button.

Another feature is a special arrangementof mounting means for theseU-shaped levers comprising a U-shaped bracket provided with a hearingpin mounted between its side members and on which one side.member ofeach U-shaped lever is rotatably mounted and an identical bracketprovided with a bearing pin on which the other side member ofeach ofsaid U-shaped levers is similarly rotatably mounted. Said brackets aresecured to the base of the telephone stand. A special U-shaped lever isalso provided having its side members mounted on one of said pins in thesame manner as the regular U-shaped levers and in position to be rotatedeach time an one of said regular U-shaped levers is rotated.

Another feature is an extension on each of said regular and specialU-shaped levers having a cam surface which acts on a corresponding setof contact springs when said levers are rotated for the establishment ofcombinations of connections to produce code impulses and for otherpurposes as required for the control of switches at a central ofiice.

The invention has been illustrated in the accompanying drawings in whichFig. 1 shows a perspective view of a telephone stand with operatingbuttons arranged in accordance with applicants invention,

Fig. 2 shows a general arrangement of the various apparatus inside ofthe telephone stand shown in Fig, 1 and embodying the mechanismscontrolled by the buttons in accordance with the applicants invention.

Fig. 3 is a side view of the telephone stand shown in Fig. 1 with a partof the housing broken away to show details of the applicants invention.

Fig. 4 is a fragmentary section taken approximately on the line 44 ofFig. 3 to show contact springs and parts of the levers and theirsupports in accordance with the applicants invention with one of thelevers in actuated position.

Fig. 5 is, a fragmentary portion of the deskstand showing the mechanismrevealed in Fig. 3 but with a button in operated position.

Fig. 6 is a fragmentary perspective of the applicants invention showingthe levers and their supports and the springs controlled by theextensions on said levers.

Referring now to the drawings, in general the desk-stand consists of ahandset I mounted in a cradle 2 forming a part of a housing 3 of thedesk-stand, the housing being mounted on a-base plate 4 and on the frontsurface of the housing 3 is shown the usual dial mechanism 6 and buttons1 arranged in a single row and other buttons 8 and 9 provided for thecontrol of the establishing of a connection, In front of the row ofbuttons 1 is a transparent plate Ill under which the designations may beplaced for the various buttons in the group 1. In Fig. 2 is shown thegeneral arrangement of the apparatus inside the desk-stand such as theringer H, induction coil 2, a switching contact arrangement l3controlled in the usual manner by the handset when placed in the cradleor removed therefrom and in general the inside view of the dia1 6 aswell as a mechanism such as the levers l5, the groups of contact springsl6 and I1 and a mounting plate I8 for the buttons as arranged inaccordance with the applicants invention.

Referring now to the applicants invention as applied to this telephonestand, each button in the row 1 consists of a cylindrical portion 2nprotruding through an opening in the slanting front portion 2| of thehousing 3. This button is provided with a flange 22 that abuts againstthe inner surface of the slanting portion 2i and with an innercylindrical portion 23 of a larger diameter than the cylindrical portion20 and a cylindrical portion 24 somewhat smaller than the portion 23.Around the portions 23 and 24 is wrapped a helical spring 25 that abutsat one end against the flange 22 and at the opposite end against themounting plate [8 secured to the front portion 2| of the telephonestand. Portion 24 protrudes through an opening in this mounting plate l8so that the button may be depressed to ride in this opening in mountingplate l8 and the opening in the front portion 2| and be returned tonormal position by the tension in spring 25. The normal position of thebutton is determined by the flange 22 and the depressed position isdetermined by the shoulder formed between portions 22 and 23 when thisshoulder touches the plate |8.

The regular levers I controlled by the buttons are four in number, areU-shaped and located side by side with their bottom portions parallel tosimilar to spring 55 for extensions 40 and 43 are connected to pin 57 onbracket 33.

This arrangement of buttons, levers and contact springs may be employedin the establishing of telephone connections at a central ofiice, towhich the telephone set in the stand shown may be connected by a line,and each button may, when depressed, transmit a different digit asrepresented by a particular code of impulses produced in the line by theparticular combination of contact springs operated. As an example of thetype of code or impulses that may be Y produced by the depression of thedifferent keys each other and with the left-hand side members mounted ona pin 36 secured between the side member of a U-shaped bracket 3| whichin turn is secured to the base plate 4 of the desk-stand. Similarly theright-hand side members of these levers |5 are mounted for rotation onthe pin 32 secured between the side members of a similar U- shapedbracket 33 which is also secured to the base plate 4 of the telephonestand. It will be noted that the bottom members of these U -shapedlevers l5 are provided with projections or fingers such as 36, 31 andothers in various positions. Some of these are bent inwardly and othersare projecting straight from the levers. These extensions are soarranged that the bottom surface of each button portion 24 will engageone or more of these projections 50 that when any one of these buttonsis depressed it will rotate a certain combination of these leversdepending on the number of projections on the levers that are engaged bythe bottom surface thereof.

Each of the U-shaped levers I5 is provided with an extension member sucha 40, for example, on the outside U-shaped member 4| or extensions 42,43 and 44 on the other levers I5. It will also be noted that on the pin30 of the bracket 3| is mounted an additional U-shaped lever 45. Thebottom portion of this lever 45 extends under the side members of theother four levers i5 so that when any one of these four levers or anycombination thereof are rotated, the lever 45 will also be rotated onthe pin 30. The lever 45 is also provided with an extension 46 similarto the extensions 40, 42, 43 and 44 on the other levers l5. Each of thelevers I5 and the lever 45 at their extensions 40, 42, 43, 44 and 46 areprovided with angular projections bent to form cam surfaces such asprojection 48 for the extension 43 and projection 45 for the extension45. These projections operate through their cam surfaces on studsconnected to contact springs. For example, the cam surface On projection49 operates on the stud 50 connected to contact spring 5| so that whenthe associated lever 45 rotates, this cam surface will move the contactspring 5| to disconnect from contact spring 52 and connect with contactspring 53. Similarly when any of the other levers are rotated thecorresponding cam surfaces on the associated extensions 40, 42, 43 and44 will operate on similar contact springs in the groups IE or I! ashown particularly in Figs. 2 and 6. All of the levers are maintained innormal position by springs such as for example 55 connected to theextension 46 at one end and at the other end connected to pin 56 betweenthe side members of the bracket 3|. It will be noted that springssimilar to spring 55 for the extensions 42 and 44 are also connected topin 56 on bracket 3| and that springs to operate difierent combinationsof contact springs, an alternating current source may be connected tothe usual two-wire telephone line conductors at a central office towhich the telephone set is connected and rectifiers, four for example,may be interposed between the line conductors and ground through thecontact springs controlled by the buttons. Thus by operating differentcontact springs in combination positive or negative impulses or both maybe transmitter over one or both of the lines in different combinations.For example, if the fifteenth key -is operated all fivecontacts in thesets I6 and I! may be operated to connect the four rectifiers to theline conductors through the contacts to transmit positive and negativeimpulses on each line. On the other hand if, for example, the first keyis operated positive impulses only are sent over one of the lineconductors. 1 Code impulse transmitting key arrangements demonstratingthis general principle of code impulse transmission are disclosed insuch patents as 2,278,410 of April '7, 1942, to H. M. Bascom et al. and2,349,129 of May 16, 1944, to W. T. Albert. The designation of eachsubscriber may be imprinted on a card located under the transparentplate In in the form of a numeral as by the name of the subscriber. Inthe arrangement of the buttons as disclosed in Fig. 1, it may beobserved that there are fifteen buttons in all in a single row and thatthese buttons are divided in three groups of five each with a greaterspace between the groups than between the individual buttons in thegroups. This is a decidedly advantageous arrangement as it enables theoperator of the buttons to more easily locate the desired party ornumber and the fact that the buttons are located on the slanting frontface of the telephone stand also aids in the manipulation of thebuttons.

What is claimed is:

1'. In a telephone stand, a set of yokes, each consisting of a thinstrip of flat material having a relatively long intermediate section andend sections formed by right angle bends, a common pivot support onwhich one end section of each of said yokes is mounted for rotation, asecond common pivot support on which the other end of each of said yokesis mounted for rotation, the length of the end sections of said yokesdiminishing progressively from one yoke to the next to provide aparallel disposition of the intermediate sections with freedom for eachyoke to move about said pivot supports independently of the other yokes,the intermediate sections of each yoke being formed with integralprojections which are disposed in groups representing desiredcombinations of said yokes, a series of cylindrical push buttonsarranged close together in a straight line parallel to the intermediatesections of saidyokes, there being a push button for each of said yokesof projections, the

bottom end of each button serving to operate a combination of yokesthrough the medium of said integral projections and having an areasufficient to embrace only a portion of the integral projections ofgroups representing certain desired combinations, the projection on atleast one yoke for each of said certain combinations being bent inwardlytoward the other projections of such combination to effect aconcentration of said projections and to bring all of them within theworking area of the corresponding button, sets of contact springsmounted in said stand, and cam-shaped extensions on the end sections ofsaid yokes which serve to operate said contact springs in desiredcombinations when the corresponding yokes are rotated by the depressionof the associated push button.

2. In a telephone stand, a set of yokes, each consisting of a thin stripof flat material having a relatively long intermediate section and endsections formed by right-angle bends, a common pivot support on whichone end section of each of said yokes is mounted for rotation, a secondcommon pivot support on which the other end section of each of saidyokes is mounted for rotation, the length of the end sections of saidyokes diminishing progressively from one yoke to the next to provide aparallel disposition of the intermediate sections with freedom for eachyoke to move about said pivot supports independently of the other ofyokes, the intermediate stations of each yoke being formed with integralprojections, the projections on all but one of said intermediatesections extending straight upward from said sections and theprojections on the remaining intermediate section being bent over theother intermediate sections, all of said projections being disposed ingroups, representing desired combinations of said yokes, a series ofcylindrical push buttons arranged close together in a straight lineparallel to the intermediate sections of said yokes, there being a pushbutton for each of said groups of projections, the bottom end of eachbutton serving to operate a combination of yokes through the medium ofsaid integral projections and having an area which has a diameter equalto the distance between the maximum number of straight projectionspossible for all but said one intermediate section when said straightprojections are arranged one in front of the other perpendicularlyacross said sections, said area being nevertheless suflicient to controla bent projection on the remaining intermediate section when located onone side of the associated straight projections, sets of contact springsmounted in said stand, extensions extending in a straight line from theend sections of said yokes, and cam members extending perpendicularlyfrom the ends of said extensions of the end sections which serve tooperate individual sets of contact springs in desired combinations whenthe corresponding yokes are rotated by the depression of the associatedpush button.

HARRY HANSEN. RUDOLPH F. MALLINA.

